Grate for shaft furnaces



mws

H. STEHMANN GRATE FOR SHAFT FURNACES Filed Aug. I?7 1919 Patented Apr. 17, 1923.

HARRY STEHMANN, OF BEaLIN-HoHENscHoNHaUsEN, GER ANY.

GRATE FOR SHAFT FURNACES.

i Application filed August 1, 1919. Serial No. 314,?86.

(GRANTED UNDER THE PROVISIONS OF THE AUT OF lfiARCH 3, 1921, 41 STAT. I., 1313.)

To al? whom it may con/cara:

Be it known that I, HARRY STEHMANN, engineer, a citizen ot the German State and resident of Berlin-Hohenschonhausen, Germany, have invented certain new and useful lmprovements in Gretes for Shaft .Furnaces (for which applications for patents have been filed in Germany, 7 July, 191t 10 Feby.,

1915, and 3 Nov., 19.15; in Austria, 8 July, 10 1915; in Hungary, 9 July, 1915, and 22 Jany., 1916; in Switzerland, 24 October, 1918; in Denmark, 24 October, 1918; in Norway, 29 October, 1918; in Sweden, 30 October, 1918; in Spain, 26 November, 1918; and in Belgium 25 November, 1918) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The problem met in sintering shaft kilns, such as for sintering magnesite, cement and the like, where fusion of the mass treated is not contenplated, has been the reinoval of the sintered product from below the sinter ing zone in a constant and uniform manner.

The sinter block below the sintering zone should descend in the kiln to maintain the sintering zone above the block or mass at about a stationary height notwithstanding the constant removal of sintered product at the bottom, and a constant supply of raw material at the top of the kiln.

I have discovered that if the entire kiln content is supported over the entire kiln cross section at the bottom on crushing rolls, that the sintered base of the charge will be uniformly broken away on its under surface and discharged, the weight of the charge forcing the sintered mass continually against the rolls. This insures a unform breaking away of the sinter at the bottom of the charge over the whole area; the charge sinks uniformly and the sintering zone remains about stationary in position without being extended upwardly or downwardly, or both, as is often the case When the breaking away of the sinter does not eXtend over the whol cross-sectonal area of the kiln.

I have thus solved one of the most troublesome problems in the operation of sintering sha-ft kilns.

In the accompanying` drawing I have illustrated a mechanism :tor effecting the result desired in a simple and efficacious manner.

Figure 1 is a vertical section of the lower part of a shaft kiln emboclying my invention. I

Fi 2 is a plan view oi' Fig. 1, being a section on line A B of Figure 1.

Fig. 3 is a cross section of one form of crushing roll differng from that shown in Fig. l. 4

Fig. 4 is an elevation of Fig. 3.

In the particular instance illustrated the kiln has in the bottom of its shaft four cooperating crushing rolls a mounted in shafts 72` extending through the masonry of the kiln. and each shatt has on it. outside the kih, a gear wheel, (2 The ;gear wheels 0 and 0 intermesh, and the gear wheels and 6 intermesh. The gear wheels 0 and 0 are each positively driven by a worm e, and the two worms e are mounted on a shait that is provided with a pinion (Z which in turn is driven by a worm on a shaft provided with a driving pulley.

Instead of making the crushing roll solid and providing it with peripheral crushing teeth as in Fig. 1, it may be constructed hollow, as in Figs. 3 and 41. in which case the shatt ?2 is provided with spiders 'i having openings m through them, with spaced bars in extending` parallel to the shaft across the spiders, so that the sinter may pass through as well as between' the crushin: rolls.

Below the crushing rolls a` I pi'efer to mount a ;grate-like concave 7 ,eenerally contorming to the under surface ot the crushim: roll assembly, and with which the rolls a co-operate to again arush the sinter after it has passed between or 'between and through the rolls; and below the concave f 'is a discharge hopper or bin g.

I claim- 1. The combination with a kiln shai't, of a series of continuouslv rotating co-operating elinker-removing crushing rolls extendinp; over the whole cross sectional area of the kiln and supporting the kiln charge.

2. The combination with a shaft kile; of

a series of co-operating clinker'removing orushing rolls extending over the cross-sectional area of the kih, and a grinding conoave below said rolls and (zo-Operating there- With.

3. The oombination With a shaft kiln; of

a series of co-operating clinker removing crushing roils extending over the cross-seotional area of the kiln, a grinding concave below said rolls and cooperating therewith and means to continuously rotate said rolls.

4. A shaft kiln having a series of co-operating crushing rolls extending over` the cross-seotiona1 area of the kilo and supportrolls, and means to continuously rotate said rolls.

6. A shaft kiln having a series of co-operating orushing rolls extending over the entire crosssecton of the kiln and supporting the charge said rolls each comprising a shat spiders thereon and bars extending across said spiders.

7. A shaft kiln having a series of co-operating crushing rolls extending over the entire cross-section of the kiln` and supporting the charge, said rolls each comp'rising a. sha't spiders thereon and bars' extending across said spiders, and a grinding concave in crushing relation to said rolls.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribingwitnesses.

" p HARRY STEHMANN.

Wtnesses:

MARTHA BARFELT, M'LLER. 

